Stand-alone discharge capacity tester

EcuBebge · 2019-06-10T20:14:55.000Z

After doing a fair bit of research, asking for recommendations here (thanks for your responses), and watching a decent amount of reviews on YouTube, I recently purchased the updated MiBoxer C4-12. Having had it for only a short period, I’m pleased with it’s ease of use and overall performance. However, the unit does lack discharge capacity testing which was pointed out to me prior to my purchase. The reason I ultimately settled on this unit despite it missing that feature, was that I had seen a lot of skepticism in regards to the accuracy of the discharge capacity tests of other chargers that I was recommended.

However, I have recently ventured into the world of cell harvesting from old laptop battery packs, and am finding discharge capacity testing not only useful, but necessary. The question I pose to the forum is this: Is there such a thing as a stand-alone discharge capacity tester that has consistent and reliable accuracy? Does such a thing exist with multiple bays? (and last, but certainly not least) Is there a unit that can be had for a reasonable price?

Any thoughts or recommendations would be greatly appreciated.

RobertB · 2019-06-10T21:59:40.000Z

West Mountain Radio makes some good battery analyzers

flydiver · 2019-06-10T23:06:15.000Z

Just get a Lii-500. If you need more amp discharge, get the Opus BT-C3100.
Perfect? No.
Good enough for that? Yes.
Anything that is much better will be much more expensive or limited to one cell at a time.
These are harvested cells. You are separating the decent from the junk, not the kings from the princes.

EcuBebge · 2019-06-10T23:45:33.000Z

Thanks for putting it into perspective.

Pete7874 · 2019-06-11T00:15:36.000Z

flydiver:

These are harvested cells. You are separating the decent from the junk, not the kings from the princes.

LOL! Nicely put.

OP, if you want something that can discharge at higher current, this one might do the trick. You’d just need to get a battery holder for it. No idea how accurate it is:

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However, typically laptop pulls aren’t going to be high current capable cells anyway, so I’m not sure you’d want to test them using high discharge current anyway.

I do all my capacity testing on Lii-500.

RobertB · 2019-06-11T00:20:58.000Z

Max discharge on the Opus is 1A for 1 cell at a time. Down to .3A for all four, if I remember correctly. So it all depends what kind of load you want to test them at. One of those harvested cells might test fine at half an amp, but fall over dead at 4A. Common for our flashlights to pull 2A or more.

You never mentioned your budget or actual needs

EcuBebge · 2019-06-11T01:27:19.000Z

Sorry; budget wise I’d like to stay as cheap as possible with my top end around $50.

As far as load testing I’ll admit I’m pretty new to this endeavour, so I hadn’t considered that aspect, as I was more focused on weeding out cells with lower capacity. What would you recommend as far as capabilities for this type of testing?

tatasal · 2019-06-11T14:08:21.000Z

RobertB:

Max discharge on the Opus is 1A for 1 cell at a time. Down to .3A for all four, if I remember correctly. So it all depends what kind of load you want to test them at. One of those harvested cells might test fine at half an amp, but fall over dead at 4A. Common for our flashlights to pull 2A or more.

You never mentioned your budget or actual needs

The Opus BT-C3100 v2.2 can discharge 4 x 1A simultaneously, among other modes and combinations of modes.

BlueSwordM · 2019-06-11T14:09:21.000Z

@EcuBebge, do you want the absolute best accuracy?

If so, then a constant current tester would be your best bet, and would measure internal resistance very accurately if properly setup.

flydiver · 2019-06-11T14:37:24.000Z

BlueSwordM:

@EcuBebge, do you want the absolute best accuracy?
If so, then a constant current tester would be your best bet, and would measure internal resistance very accurately if properly setup.

Per @BlueSword suggestion I got one of these: https://www.ebay.com/itm/DC-12V-Battery-Capacity-Tester-Battery-Life-Internal-Resistance-Analyzer/263358206343?ssPageName=STRK%3AMEBIDX%3AIT&\_trksid=p2057872.m2749.l2649

(There are other models). HJK did a review of one: Test/Review of Electronic load 60W
You have to add a power unit, and a cell holder of some sort. Then it only does one at a time, so it’s kinda slow. You can also do internal resistance accurately, but you need a special cell holder for that. I got one of these, but haven’t set it up yet. 4-wire Test Stand Battery Holder for 26650,18650, AA, AAA, Button Battery 5A | eBay

Total cost will likely be a bit more than a new analyzing charger.

Frankly, if you haven’t messed with this stuff you are likely to find it confusing to start. I did. There are enough youtube videos and reviews to work it out if you take the time. I’m having an interesting time going through my cells……but it’s going to take forever, as in a month of continuous operation.

That’s why I suggest you just get a good analyzing charger and go with it, at least for now. It’ll do the job ‘well enough’, and you’ll have another charger. Personally I’d get the Zanflare C4. It does everything the Lii-500 does and the IR works reasonably.

BlueSwordM · 2019-06-11T14:39:49.000Z

Yeah, it can work very well if properly setup, like mine.

Massive post on where to get lithium-ion batteries everywhere in the world! Look at Post 2-5 for info, And Canada Post 123 Rechargeable Batteries

So, now, some capacity tests! I’m using my own battery holder with my own large Beryllium Copper spring, which allows accurate capacity testing up to 3A without a 4 wire method. -I first started testing the NCR18650GA at 2A current, with a charge voltage of 4,185V and ending voltage of 2,6V. Capacity at 2,6V, being 3308mAh. [image] Energy at 2,6V, being 11,56Wh. [image] Capacity at 2,8V to compare with HKJ. [image] Nothing checks out, so I can confidently say NCR18650GAs from the Aliya …

Massive post on where to get lithium-ion batteries everywhere in the world! Look at Post 2-5 for info, And Canada Post 123 Rechargeable Batteries

INTERNAL RESISTANCE TESTING FOR THE SAMSUNG 30Q Here is a chart with some DC internal resistance values. The 30Q has 21mOhms of internal resistance according to this graph. [image] And with my measurement, a minimum measured DC internal resistance of 21mOhm! [image] Right on spec! Actually, better than most 30Qs. I can therefore say again, that the 30Q from the Aliya Battery Store is a legit cell. So, for Canadians all around the country, you can be assured to get …

EcuBebge · 2019-06-12T20:29:01.000Z

At this point I’m really only looking for something that is accurate within 5% or so. Also wanting the ability to test multiple cells at once, so I’ll probably just end up going with the Zanflare or Opus for the time being.

RobertB · 2019-06-12T21:29:32.000Z

tatasal:

RobertB:

Max discharge on the Opus is 1A for 1 cell at a time. Down to .3A for all four, if I remember correctly. So it all depends what kind of load you want to test them at. One of those harvested cells might test fine at half an amp, but fall over dead at 4A. Common for our flashlights to pull 2A or more.

You never mentioned your budget or actual needs

The Opus BT-C3100 v2.2 can discharge 4 x 1A simultaneously, among other modes and combinations of modes.

Ok, thanks. I couldn’t remember. Either way, it wouldn’t be great for harvested cells to see if they can handle a load. 1A is nothing

robk · 2019-06-22T22:51:36.000Z

If you want something cheaper but in my experience quite usable, there is now an Allmaybe (Xtar) TC2 charger, 2 slot, that can charge the battery fully, run a discharge test at I believe .5 amp, and then fully charge the battery back.It can also be used as just a normal charger, one button, you can choose between “charge” and “test”. The downside to this approach, not just for this unit, is it is slow. Expect it to take overnight. Do not leave NiMH in since it maintains a trickle charge and will not do them good. Link to Henrik’s review

https://lygte-info.dk/review/Review%20Charger%20Allmaybe%20TC2%20UK.html

Barkuti · 2019-06-23T02:38:39.000Z

EcuBebge:

At this point I’m really only looking for something that is accurate within 5% or so. …

5% is crazy inaccurate. My Lii-500's top drifting and less optimistic channel deviates less than −2%. I'd buy it again, the inaccurate internal resistance measurement is no problem anyways, I just use it to make sure the cell is well seated in the slot and the contacts are clean.

Other chargers may be more accurate but they're still @#$% in that regard. There is no way to make proper battery internal resistance measurement when contacts and rail resistance are of close order of magnitude to cell/battery ones. Other ways are required.